Fishes · Bony fishes · Lefteye flounders

Intermediate Flounder

Asterorhombus intermedius (Bleeker, 1865)
syn. Arnoglossus intermedius, Asterorhombus stellifer, Engyprosopon intermedius, Platophrys intermedius
up to 20 cm1-96 mLeast Concern
625

The Intermediate Flounder (Asterorhombus intermedius) is a flatfish with both eyes positioned on the left side of its head. Its body features a pattern of grey spots with black dots and dark edges, providing effective camouflage. A distinctive anatomical detail is a nearly continuous bony ridge extending from the front of the lower eye to the back of the upper eye. The interorbital space is narrow, always wider than the diameter of its largest eye. The species lacks dorsal and anal spines, possessing 77 to 84 dorsal soft rays and 55 to 62 anal soft rays. This diurnal flatfish reaches a maximum length of 20 cm (8 inches) and preys on benthic invertebrates. It inhabits sandy and muddy bottoms in protected bays and lagoons at depths ranging from 1 to 96 meters (3 to 315 feet). An Indo-Pacific species, A. intermedius is found from the 🌊 Red Sea to 🇹🇴 Tonga, and north to southern 🇯🇵 Japan and south to the Indo-Australian Archipelago. The genus name Asterorhombus derives from the Greek 'aster' (star) and 'rhombos' (parallelogram), reflecting its shape and general appearance.

The genus. Asterorhombus Tanaka 1915 - aster (star). ETYFish

The species. Asterorhombus intermedius (Bleeker 1865) - intermediate. ETYFish

How to recognise it
  • grey spots with black dots and dark edges
  • bony ridge from lower eye to upper eye
  • narrow interorbital space wider than largest eye

Why it's threatened

No major threats are known for this species. This is a relatively small-sized flatfish (up to 20 cm SL) that occurs mostly in shallow waters (usually to 40 m but can occur as deep as 96 m). It is mostly taken by divers and may occur as by-catch in demersal trawls conducted in some areas where it occurs. Furthermore, it occurs in seagrass beds and would be susceptible to destructive practices impinging on these habitats.

Threat classification from the IUCN Red List.

Comments

Please, sign in to leave a comment

Continue with a social account — yours will be created automatically.

No comments yet — be the first.

Last Update: August 7, 2026